When a director who never ever blinks takes on a horrific subject, a nightmare in broad daylight is the inevitable result. Welcome, if that is the right word, to the world of "12 Years a Slave."

Based on an 1853 memoir detailing the appalling experiences of Solomon Northup, a free man of color who was brazenly abducted and sold into slavery, this film intends to do more than tell us a story. It wants to immerse us in an experience, and it does.

Obviously, no film can re-create the unspeakable degradation of one human being owning another, but in making the attempt "12 Years" insists we feel things in a particularly oppressive way. This is impressive filmmaking, but it is not easy to take in.

British director Steve McQueen, working from a screenplay by John Ridley, has no intention of making audiences the slightest bit comfortable with this terrible story, no interest in putting in any special pleading to bend our hearts.

A former video artist who won Britain's prestigious Turner Prize for artists under 50, McQueen wants us to experience these horrors as intensely as he does, as intensely, if it comes to that, as Northup did himself.

Viewers of McQueen's previous films will not be surprised by any of this, by the unflinching way, for instance, it depicts the details of savage whippings the slaves endure. Both "Hunger," about the grueling hunger strike of the IRA's Bobby Sands, and "Shame" about the pain of sexual addiction, share this film's implacable style.

All three of McQueen's works also share a second element, the irreplaceable acting of Michael Fassbender, who made a huge impact as the star of "Hunger" and has formed a powerful aesthetic bond with his director at least as tight and productive as the celebrated link between Martin Scorsese and Robert De Niro.

Before we get to Fassbender, however, "12 Years" introduces another exceptional actor, Chiwetel Ejiofor, who plays Northup. Impressive in films such as "Dirty Pretty Things" and "Children of Men," Ejiofor is a supple actor whose subtle work conveys the mind-bending notion of a man born free but hijacked into slavery, a man who finds the keystones of his identity ripped away from him, possibly never to return.

Because the arc of Northup's nightmare is revealed in the title of both the film and the memoir, it is a special challenge for "12 Years" to involve us in specific ups and downs given that we know how it all ends.

Potent performances across the board make that happen. Whether it's established folks like Ejiofor, Fassbender and producer Brad Pitt (in a key cameo that helped get the film made) or relatively new faces such as Lupita Nyong'o and Adepero Oduye, everyone fits smoothly into the deliberate pace of McQueen's measured and solemn direction.

Though Northup's memoir is strictly chronological, Ridley's screenplay shrewdly starts us in the middle of the story, with Northup well into his new identity as Platt the slave deep in the bayous of Louisiana. At night he shares a moment of desperation with a female slave that offers a kind of relief but ends only in increased despair.

Once "12 Years" has shown us this vignette, it is doubly shocking to flash back to Platt's life when he was Northup, a free man in Saratoga Springs, N.Y., with a wife and two children and an apparently steady source of income as a fiddler. "Stay safe," his wife says as she heads off to a multi-week job as a cook. They are the last words of hers he will hear for quite awhile.

A chance meeting with a pair of seemingly upstanding white men who offer him the chance of employment leads to a trip to Washington, D.C., which ends with Northup being drugged and awakening chained in a slave pen, with no one to appeal to and savage beatings assured every time he insists he is not a runaway. This is the classic "wrong man" theme raised to an unendurable level.

Except Northup, now renamed Platt, has no choice but to endure it. Especially disturbing is the casual but complete dehumanization he finds being a slave means, with slave trader Freeman (an excellent Paul Giamatti) offering him and others for sale with a casual "what catches your fancy, inspect at your leisure."

Platt's first master, William Ford (the ever-present Benedict Cumberbatch), is relatively enlightened by slave owner standards, but even he can only do so much when Platt gets into a bitter dispute with a thoroughly racist overseer (an adept Paul Dano). No one inside the system can escape its corruption and its power.

Edwin Epps, Platt's next owner, is altogether different. A notorious and psychotic slave breaker, Epps, superbly acted by the fearless Fassbender, is the absolute ruler of a disturbing alternate universe of his own devising, one characterized by his alternating passion for and disgust with the slave Patsy (Nyong'o), his sexual chattel as well as the best field hand on his plantation.

Effectively shot by McQueen's longtime cinematographer Sean Bobbitt on several real Louisiana plantations, "12 Years" explores a number of odd corners of the slavery situation, like the slave Mistress Shaw (Alfre Woodard) who is married to the plantation owner and serves an elaborate tea on Sunday mornings.

Though he insists to himself "I will not fall into despair," this proves increasingly difficult for Platt as the unimaginable things he has to do to survive mount almost beyond understanding. Uncompromising to the end, "12 Years" insists on saying to us, this was how it was, deal with it.